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Study of the statistics of water vapor mixing ratio determined from Raman lidar measurements / Pierre Bosser in Applied Optics, vol 46 n° 3 ([20/11/2007])
[article]
Titre : Study of the statistics of water vapor mixing ratio determined from Raman lidar measurements Type de document : Article/Communication Auteurs : Pierre Bosser , Auteur ; Olivier Bock , Auteur ; Christian Thom , Auteur ; Jacques Pelon, Auteur Année de publication : 2007 Article en page(s) : pp 8170 - 8180 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement du signal
[Termes IGN] données GPS
[Termes IGN] données météorologiques
[Termes IGN] erreur systématique
[Termes IGN] étalonnage des données
[Termes IGN] lidar Raman
[Termes IGN] rapport signal sur bruit
[Termes IGN] signal GPS
[Termes IGN] teneur en azote
[Termes IGN] teneur en vapeur d'eauRésumé : (auteur) The statistical properties of atmospheric water vapor mixing ratio (WVMR) determined as the ratio of Raman lidar signals backscattered from water vapor and nitrogen molecules are studied. It is shown that WVMR estimates can be biased by a small percentage at low signal photon-counting rates due to fluctuations in the nitrogen signal in the denominator of the ratio, the magnitude of the bias being linked to the signal-to-noise ratio of the nitrogen signal. This is particularly important when unbiased estimates are required as in the case of climate studies and global positioning system (GPS) signal calibration. Different bias corrections and a modified ratio formulation are proposed in order to correct or eliminate this bias. The method is successfully applied in processing signals obtained with an experimental Raman lidar system devoted to calibrate GPS signals for slant path delays. It is shown to reduce biases into negligible values in both WVMR and wet path delay estimates in the range interval of 0–7 km. Numéro de notice : A2007-669 Affiliation des auteurs : LOEMI+Ext (1985-2011) Thématique : POSITIONNEMENT Nature : Article DOI : 10.1364/AO.46.008170 Date de publication en ligne : 19/11/2007 En ligne : https://doi.org/10.1364/AO.46.008170 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84150
in Applied Optics > vol 46 n° 3 [20/11/2007] . - pp 8170 - 8180[article]Spectral analysis of coastal vegetation and land cover using AISA+ hyperspectral data / R. Jensen in Geocarto international, vol 22 n° 1 (March - May 2007)
[article]
Titre : Spectral analysis of coastal vegetation and land cover using AISA+ hyperspectral data Type de document : Article/Communication Auteurs : R. Jensen, Auteur ; P. Mausel, Auteur ; N. Dias, Auteur ; et al., Auteur Année de publication : 2007 Article en page(s) : pp 17 - 28 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] étalonnage des données
[Termes IGN] image AISA+
[Termes IGN] image hyperspectrale
[Termes IGN] mangrove
[Termes IGN] réflectance végétale
[Termes IGN] Texas (Etats-Unis)Résumé : (Auteur) This paper describes a spectral analysis of several coastal land cover types in South Padre Island, Texas using AISA+ hyperspectral remote sensing data. AISA+ hyperspectral data (1.5 metre) were acquired throughout the area on 9 March 2005. Data over mangrove areas were converted to percent reflectance using four 88 metre reflectance tarps (4%, 16%, 32% and 48%) and empirical line calibration. These data were then compared to percent reflectance values of other terrestrial features to determine the ability of AISA+ data to distinguish features in coastal environments. Results suggest that these data may be appropriate to discriminate coastal mangrove vegetation and provide researchers with high resolution spatial and spectral information to more effectively manage coastal ecosystems. Copyright Taylor & Francis Numéro de notice : A2007-457 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106040701204354 Date de publication en ligne : 24/05/2007 En ligne : https://doi.org/10.1080/10106040701204354 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28820
in Geocarto international > vol 22 n° 1 (March - May 2007) . - pp 17 - 28[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 059-07011 RAB Revue Centre de documentation En réserve L003 Disponible An Improved mean-gravity model for GPS hydrostatic delay calibration / Pierre Bosser in IEEE Geoscience and Remote Sensing Letters, vol 4 n° 1 (2007)
[article]
Titre : An Improved mean-gravity model for GPS hydrostatic delay calibration Type de document : Article/Communication Auteurs : Pierre Bosser , Auteur ; Olivier Bock , Auteur ; Jacques Pelon, Auteur ; Christian Thom , Auteur Année de publication : 2007 Article en page(s) : pp 3 - 7 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] étalonnage des données
[Termes IGN] hauteur ellipsoïdale
[Termes IGN] incertitude géométrique
[Termes IGN] modèle atmosphérique
[Termes IGN] précision submillimétrique
[Termes IGN] radiosondage
[Termes IGN] retard troposphérique
[Termes IGN] retard troposphérique zénithal
[Termes IGN] variabilité
[Vedettes matières IGN] Traitement de données GNSSRésumé : (auteur) The determination of global positioning system (GPS) heights with submillimeter accuracy needs proper correction of tropospheric delay. In this letter, the modeling of zenith hydrostatic delay (ZHD) was addressed, considering that wet delay must be treated separately. ZHD is traditionally estimated from Saastamoinen's formula using a mean-gravity model and surface pressure observations. The uncertainty in ZHD associated with the mean-gravity model is about 0.3 mm. An improved parametric model is derived here, which yields an uncertainty in the ZHD less than 0.1 mm when the surface altitude lies in the range of 0-9 km. A second parametric model is derived for higher altitudes (such as above radiosonde observations or atmospheric models). Both parametric models depend on latitude, height, and time variables. This dependence is due to the link between the mean gravity and temperature profiles between the surface and ~80-km altitude. The uncertainty in the parametric models due to short-term temporal variability of the temperature profiles is shown to produce an uncertainty in ZHD smaller than 0.1 mm. Numéro de notice : A2007-668 Affiliation des auteurs : LOEMI+Ext (1985-2011) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/LGRS.2006.881725 Date de publication en ligne : 15/01/2007 En ligne : http://doi.org/10.1109/LGRS.2006.881725 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84147
in IEEE Geoscience and Remote Sensing Letters > vol 4 n° 1 (2007) . - pp 3 - 7[article]Determination of the mean sea level at Algiers Harbour from the tidal data analysis / M. Haddad in Bulletin des sciences géographiques, n° 18 (octobre 2006)
[article]
Titre : Determination of the mean sea level at Algiers Harbour from the tidal data analysis Type de document : Article/Communication Auteurs : M. Haddad, Auteur ; Hassen Abdellaoui, Auteur Année de publication : 2006 Article en page(s) : pp 18 - 20 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique
[Termes IGN] Alger
[Termes IGN] analyse harmonique
[Termes IGN] données altimétriques
[Termes IGN] étalonnage des données
[Termes IGN] marégraphe
[Termes IGN] niveau moyen des mers
[Termes IGN] port
[Termes IGN] réseau altimétrique nationalRésumé : (Auteur) The present study aims at defining a national sea level reference in Algeria and can be integrated in other oceanographic projects for determination of the mean sea level. Whatever the principle of measure is, a tide gauge is able to provide a local information on the height of the sea referred to the chosen reference. The main points of this study are: the calibration of the data of the electronic tidal gauge with an automatic data acquisition System installed in Algiers harbour; the comparison of these data with the data acquired from the analogical tidal gauge installed on the same site; and the determination of the mean sea level using the harmonic analysis. The exploitation of the data recorded with the electronic tide gauge of Algiers during a period of two years provide an estimate of the mean sea level and the harmonic components which can be also used for the prediction. The estimated mean sea level differs by a few centimeters of the actual value currently used which was determined in a "arbitrary" way. Numéro de notice : A2006-520 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28243
in Bulletin des sciences géographiques > n° 18 (octobre 2006) . - pp 18 - 20[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 253-06021 RAB Revue Centre de documentation En réserve L003 Disponible An empirical investigation of cross-sensor relationships of NDVI and red/near-infrared reflectance using EO-1 Hyperion data / T. Miura in Remote sensing of environment, vol 100 n° 2 (30 January 2006)
[article]
Titre : An empirical investigation of cross-sensor relationships of NDVI and red/near-infrared reflectance using EO-1 Hyperion data Type de document : Article/Communication Auteurs : T. Miura, Auteur ; A. Huete, Auteur ; Hiroki Yoshioka, Auteur Année de publication : 2006 Article en page(s) : pp 223 - 236 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse comparative
[Termes IGN] bande rouge
[Termes IGN] Brésil
[Termes IGN] étalonnage des données
[Termes IGN] filtre passe-bande
[Termes IGN] flore locale
[Termes IGN] forêt tropicale
[Termes IGN] image EO1-Hyperion
[Termes IGN] image hyperspectrale
[Termes IGN] image Landsat-ETM+
[Termes IGN] image Terra-MODIS
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] rayonnement proche infrarouge
[Termes IGN] réflectance spectrale
[Termes IGN] savaneRésumé : (Auteur) Long term observations of global vegetation from multiple satellites require much effort to ensure continuity and compatibility due to differences in sensor characteristics and product generation algorithms. In this study, we focused on the band-pass filter differences and empirically investigated cross-sensor relationships of the normalized difference vegetation index (NDVI) and reflectance. The specific objectives were: 1) to understand the systematic trends in cross-sensor relationships of the NDVI and reflectance as a function of spectral band-passes, 2) to examine/ identify the relative importance of the spectral features (i.e., the green peak, red edge, and leaf liquid water absorption regions) in and the mechanism(s) of causing the observed systematic trends, and 3) to evaluate the performance of several empirical cross-calibration methods in modelling the observed systematic trends. A Level 1A Hyperion hyperspectral image acquired over a tropical forest-savanna transitional region in Brazil was processed to simulate atmospherically corrected reflectances and NDVI for various band-passes, including Terra Moderate Resolution Imaging Spectro-radiometer (MODIS), NOAA-14 Advanced Very High Resolution Radiometer (AVHRR), and Landsat7 Enhanced Thematic Mapper Plus (ETM+). Data were extracted from various land cover types typically found in tropical forest and savanna biomes and used for analyses. Both NDVI and reflectance relationships among the sensors were neither linear nor unique and were found to exhibit complex patterns and band-pass dependencies. The reflectance relationships showed strong land cover dependencies. The NDVI relationships, in contrast, did not show land cover dependencies, but resulted in non-linear forms. From sensitivity analyses, the green peak (550 nm) and red-NIR transitional (680780 nm) features were identified as the key factors in producing the observed land cover dependencies and non-linearity in cross-sensor relationships. In particular, differences in the extents to which the red and/or NIR band-passes included these features significantly influenced the forms and degrees of non-linearity in the relationships. Translation of MODIS NDVI to "AVHRR Iike" NDVI using a weighted average of MODIS green and red bands performed very poorly, resulting in no reduction of overall discrepancy between MODIS and AVHRR NDVI. Cross-calibration of NDVI and reflectance using NDVI-based quadratic functions performed well, reducing their differences to +.025 units for the NDVI and +.01 units for the reflectances; however, many of the translation results suffered from bias errors. The present results suggest that distinct translation equations and coefficients need to be developed for every sensor pairs and that land cover-dependency need to be explicitly accounted for to reduce bias errors. Numéro de notice : A2006-034 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2005.10.010 En ligne : https://doi.org/10.1016/j.rse.2005.10.010 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27761
in Remote sensing of environment > vol 100 n° 2 (30 January 2006) . - pp 223 - 236[article]A digital camera as a tool to measure colour indices and related properties of sandy soils in semi-arid environments / N. Levin in International Journal of Remote Sensing IJRS, vol 26 n° 24 (December 2005)PermalinkWatershed scale temporal and spatial stability of soil moisture and its role in validating satellite estimates / M.H. Cosh in Remote sensing of environment, vol 92 n° 4 (30 September 2004)PermalinkComparison of Earth observing-1 ALI and Landsat ETM+ for crop identification and yield prediction in Mexico / D.B. Lobell in IEEE Transactions on geoscience and remote sensing, vol 41 n° 6 (June 2003)PermalinkPermalinkThe calibration of SAR interferometric DEM's with Differential GPS / S. Slob in GeoEurope, vol 9 n° 6 (01/06/2000)PermalinkModeling and validating orbits and clocks using the Global Positioning System / Tim A. Springer (2000)PermalinkTendances nouvelles en modélisation pour l'environnement / François Blasco (1997)PermalinkA technique for extrapolating and validating forest cover across large region : calibrating AVHRR data with TM data / Louis R. Iverson in International Journal of Remote Sensing IJRS, vol 10 n° 11 (November 1989)PermalinkField reflectance calibration with grey standard reflectors / W.R. Philipson in International Journal of Remote Sensing IJRS, vol 10 n° 6 (June 1989)PermalinkOptimum data weighting and error calibration for estimation of gravitational parameters / F.J. Lerch (1989)Permalink